Computer system having cooperating spring, gear tracks and geared dampers for allowing a drive housing to move between open and closed positions

ABSTRACT

Disclosed is a media console which includes a base member and a drive housing that can be moved within the base member between an open position and a closed position. A spring is connected to a bottom of the base member and to the drive housing for biasing the drive housing in the open position. A pair of gear tracks are integrally formed in opposite sides of the base member for cooperating with a pair of geared dampers attached to opposite ends of the drive housing. The drive housing includes a direct access storage device disposed at a front end thereof and the direct access storage device has an opening for receiving a removable storage medium. The spring, gear tracks and geared dampers cooperate with each other (1) to allow the drive housing to move smoothly from the closed position to the open position wherein a user may access the opening, and (2) to allow the drive housing to move smoothly from the open position to the closed position.

RELATED APPLICATIONS

The present invention is believed to be related to the following pendingapplications:

Application Ser. No. 08/721,651, filed Sep. 23, 1996, and entitled"SPLIT SYSTEM PERSONAL COMPUTER" (further identified as Attorney DocketNo. RP9-95-045);

Application Ser. No. 08/721,653, filed Sep. 23, 1996, and entitled"MEDIA CONSOLE FOR A SPLIT SYSTEM PERSONAL COMPUTER" (further identifiedas Attorney Docket No. RP9-95-046);

Application Ser. No. 08/721,650, filed Sep. 23, 1996, and entitled"MULTI-CONDUCTOR CABLE ARCHITECTURE AND INTERFACE FOR A SPLIT SYSTEMPERSONAL COMPUTER" (further identified as Attorney Docket No.RP9-96-009);

Application Ser. No. 08/717,558, filed Sep. 23, 1996, and entitled"METHOD FOR INTERFACING A MEDIA CONSOLE AND A SYSTEM UNIT" (furtheridentified as Attorney Docket No. RP9-96-014);

BACKGROUND Of THE INVENTION

1. Field of the Invention

The present invention relates to personal computer systems and moreparticularly to a split system personal computer which includes a mediaconsole having a direct access storage device (DASD) having an openingfor receiving a removable storage medium, the DASD disposed within adrive housing that can be moved within a base member between an openposition and a closed position, and wherein a raise/support assembly inthe media console allows the drive housing to move smoothly between theclosed position and the open position and vice-versa.

2. Description of Related Art

Personal computer systems are well known in the art. Personal computersystems in general, and IBM Personal Computers in particular, haveattained widespread use for providing computer power to many segments oftoday's modern society. Personal computers can typically be defined as adesktop, floor standing, or portable microcomputer that is comprised ofa system unit having a single central processing unit (CPU) andassociated volatile and non-volatile memory, including all RAM and BIOSROM, a system monitor, a keyboard, one or more flexible diskette drives,a fixed disk storage drive (also known as a "hard drive"), a so-called"mouse" pointing device, and an optional printer. One of thedistinguishing characteristics of these systems is the use of amotherboard or system planar to electrically connect these componentstogether. These systems are designed primarily to give independentcomputing power to a single user and are inexpensively priced forpurchase by individuals or small businesses. Examples of such personalcomputer systems are IBM's Personal Computer AT and IBM's Aptiva.

Historically, a personal computer (PC) was a relatively large box thatsat on top of a desk and contained all of the electronics--theprocessor, memory, IO devices, floppy disk drive, etc. This was known asthe system unit and required a significant amount of desktop work space.The monitor was traditionally a cathode ray tube (CRT) that was placedon top of the system unit. The keyboard and (eventually a mouse) wasplaced in front of the system unit to provide for user input.Accordingly, these "desktop" computer systems combined all PC functionsand accessibility in one enclosure on the desktop where significantspace is required and noise sources are relatively close to the user. Inaddition, there was no way to compact the elements when the PC was notin use.

In order to reduce the clutter that a personal computer caused on thedesktop, a tower design soon emerged that moved the system unitcomponents into a tower form-factor that sat along-side the desk. TheCRT now sat directly on the desk with the keyboard and mouse in front ofit. However, this "minitower" type unit is typically placed on the floorwhere accessibility to drives (floppy and CD-ROM), power, and systemactivity (LEDs) is compromised and awkward. These two form factors (the"desktop" and "minitower" systems) have endured for quite some time withjust various changes in the size, shape and color.

In addition, the above conventional desktop and mini-tower computersystems either expose all of their media devices (e.g., floppy diskdrive, CD-ROM drive) or cover the devices with a horizontally orvertically sliding door, respectively. The door, however, is undesirableduring use because it represents an additional step to open, or if leftopen, is often in the way, can easily be damaged and can requireadditional work space.

It is therefor desirable to provide a personal computer system formfactor that significantly reduces the amount of desktop space needed,and provides easy user friendly accessibility to the media devices.

SUMMARY OF THE INVENTION

The present invention is directed to a raise/support assembly for amedia console of a computer system. The media console includes a basemember and a drive housing that can be moved within the base memberbetween an open position and a closed position. A spring is connected toa bottom of the base member and to the drive housing for biasing thedrive housing in the open position. A pair of gear tracks are integrallyformed in opposite sides of the base member for cooperating with a pairof geared dampers attached to opposite ends of the drive housing. Thedrive housing includes a direct access storage device disposed at afront end thereof and the direct access storage device has an openingfor receiving a removable storage medium. The spring, gear tracks andgeared dampers cooperate with each other (1) to allow the drive housingto move smoothly from the closed position to the open position wherein auser may access the opening, and (2) to allow the drive housing to movesmoothly from the open position to the closed position.

The raise/support assembly of the present invention allows the drivehousing to reside within the base member when closed, but raise in asmooth, fluid motion from the base member when opened and remainsupported in the open position. The assembly is based on a spring thatprovides significant function without requiring several moving parts orlinkages thus providing a low complexity of assembly. The damper actionagainst the gear tracks provide effective dampening and consistentcontrol of the drive housing ascent with minimal complexity of design.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a computer system embodying the presentinvention wherein a drive housing is in an open position.

FIG. 2 is a perspective view of the media console of FIG. 1, wherein thedrive housing is in a closed position.

FIG. 3 is an exploded perspective view of certain elements of the mediaconsole of FIG. 1 including a base member, drive housing, raise/supportmechanism, a latch, electromechanical direct access storage devices andan electronic card, and illustrating certain relationships among thoseelements.

FIG. 4 is a cut-away perspective view of the media console showing thelatch of FIG. 3.

FIG. 5 is an enlarged view of the track portion of the latch of FIG. 4.

FIG. 6 is an enlarged perspective view of a portion of the front andleft sides of the media console base member showing the raise/supportmechanism in accordance with the present invention.

FIG. 7 is an exploded perspective view of certain elements of theprocessing unit of FIG. 1 including a planar board, CPU, power supply,hard disk drive, ISA interface electronic card and cover, andillustrating certain relationships among those elements.

FIG. 8 is a perspective view of an alternative embodiment of theprocessing unit of the present invention.

FIG. 9 is a block diagram showing how FIGS. 9A, 9B, and 9C fit togetherand FIGS. 9A, 9B, and 9C are a block diagram of certain components ofthe computer system of FIGS. 1 and 2.

FIG. 10 is a schematic block diagram of the ISA interface electroniccard, cable and media console electronic card of the present invention.

FIG. 11 is a cycle timing diagram of a block read I/O cycle between theISA interface in the system unit and the CD-ROM drive of the mediaconsole via the connecting electrical cable.

FIG. 12 is a table of each signal of the 10 pin planar connector on theISA interface card along with its function description.

FIG. 13 is a schematic diagram of the power distribution between the ISAinterface card and media console electronics card of the presentinvention.

FIG. 14 is table of the signal layout of the multi-conductor flexiblecable used in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention will be described more fully hereinafterwith reference to the accompanying drawings, in which a preferredembodiment of the present invention is shown, it is to be understood atthe outset of the description which follows that persons of skill in theappropriate arts may modify the invention here described while stillachieving the favorable results of this invention. Accordingly, thedescription which follows is to be understood as being a broad, teachingdisclosure directed to persons of skill in the appropriate arts, and notas limiting upon the present invention.

Referring to the accompanying drawings, a split system personal computerembodying the present invention is there shown and generally indicatedat 10 (FIG. 1). The computer system 10 may have an associated monitor12, keyboard 14, mouse 15 and printer (not shown). The computer 10includes a media console 16 which is connected to a system or processingunit 18 by a multi-conductor flexible cable 20. The media console 16 canbe placed on top of a desk near the monitor 12 and includes all of theuser interactive components of the computer system 10 including a floppydisk drive 22, CD-ROM drive 24, power on/off switch 26, statusindicators 28 (e.g., power and hard drive activity) and input deviceports (e.g., keyboard and mouse). The system unit 18 on the other handcontains all the power, bulky and noisy components that a user does notneed to interact with and can be placed under or behind the desk. Forexample, as will be described in more detail below, the system unit 18includes a central processing unit (CPU), planar, memory, hard diskdrive, expansion bus slots (PCI, ISA), expansion drive bays, powersupply, fan(s) and video/graphics subsystem.

The internal mechanical elements (described in more detail below) allowthe drive bay housing 30, which contains the floppy disk drive 22 andCD-ROM drive 24, to move between an open position shown in FIG. I and aclosed position shown in FIG. 2. In the open position, a user can accessthe openings in floppy disk drive 22 and/or CD-ROM drive 24 toinsert/remove a floppy or compact disk respectively as needed. On theother hand, in the closed position, the openings in FDD 22 and CD-ROMdrive 24 are concealed with a front panel of the base member 32 andcannot be accessed. In addition; an optional lock (not shown) can beprovided on the media console 16 to lock the drive housing 30 in theclosed position providing added security to prevent unauthorized accessto the drives 22 and 24.

The internal mechanical assembly allows the drive housing 30 to raisefrom the console base 32 in one smooth, fluid motion when unlatched andremain supported in the open position (FIG. 1). The drive housing 30 canbe raised and unlatched from the closed position (FIG. 2) to the openposition (FIG. 1) by a user simply pressing down on the push pad 34, andlowered and latched from the open position to the closed position by auser again pushing down on the push pad 34. This conserves and minimizesspace on the desktop, protects the floppy disk drive 22 and CD-ROM drive24 when in the closed position and also provides easy accessibility ofthe drives 22 and 24 to the user when needed.

The personal computer system 10 is a split system in that it separatesthe media components (e.g., floppy disk drive 22 and CD-ROM drive 24)within media console 16 from the central processing unit (CPU), harddrive and power supply which are located within the separate system unit18. In other words, the computer system 10 removes all the componentswhich a user does not need to interact with away from the desktop workspace. As a result, the components which are disposed in the mediaconsole 16 on the desktop have a much smaller profile than conventionaldesktop personal computers. (For example, the dimensions of mediaconsole 16 when the drive housing 30 is in the closed position can be 55mm high, 260 mm deep and 390 mm Wide as compared to a conventionaldesktop unit of dimensions 125 mm high, 435 mm deep and 380 mm deep.Yet, unlike the tower design, all user interaction is made easilyaccessible on the desktop without the need to reach down to a towerunit. In addition, when the computer 10 is not in use, the keyboard 14may be stored on top of the media console 16 under the monitor 12 toprovide an even more compact system. Moreover, the media console 16 isalso very low power compared to the processing unit 18 such that it doesnot produce excessive heat or require a fan.

The monitor 12 can have multimedia speakers 36 and 38 built intoopposite sides of the front thereof or the system 10 can have separatelydetached speakers (not shown) for providing sound. The monitor 12 can besuspended above the media console 16 with a cantilevered monitor stand40. The monitor stand 40 is self supportive so the monitor weight is notplaced on top of the media console 16 and allows the drive housing 30 toraise unimpeded. The stand 40 fits underneath the opposite ends of themedia console 16 to keep the monitor 12 within the same "footprint"space as the media console 16. The stand 40 can be formed from standardtubular steel with a steel plate welded to the top for use ininterfacing with the monitor's tilt swivel device (not shown).

Referring now to FIG. 3, there is shown a schematic diagram of theelements which make up the media console 16. As shown therein, the mediaconsole 16 includes a movable top cover 42 which cooperates with a basemember 32 in defining an enclosed, shielded volume for receivingelectrically powered data processing and storage components forprocessing and storing digital data. More specifically, the storagecomponents include floppy disk drive 22 and CD ROM drive 24. The floppydisk drive 22 can be a removable medium direct access storage device(DASD) capable of receiving a diskette inserted there into and using thediskette to receive, store and deliver data as is generally known. TheCD-ROM drive 24 can be a removable medium direct access storage devicecapable of receiving a compact disk inserted there into and using thedisk to deliver data as is generally known. Alternatively, either thefloppy disk drive 22 or CD-ROM drive 24 could be replaced with a digitalversatile disk (DVD) drive. The FDD 22 and CD-ROM drive 24 are mountedon a direct access storage device bracket 44. The DASD bracket 44 ismounted to the top cover 42 such that the drives 22 and 24 will movewith the top cover 42. The top cover 42 includes a user push pad 34 andis disposed between right and left wings 46 and 48 respectively.

User access features and indicators such as a power button 26 andvarious LEDs 28 (e.g., power light indicator, hard disk drive activityindicator) are included in the media console 16 operator panel 50. Astandard keyboard port 52 and mouse port 54 exit the rear of the mediaconsole 16. A media console electronics card 56 is disposed within theconsole housing 30 and is coupled to the floppy disk drive 22 and CD ROMdrive 24. The card 56 is also connected to multi-conductor cable 20 viaconnector 58. As will be described in more detail below, the electronicscard 56, in cooperation with an interface in the processing unit 18, isused to receive address and data information from the processing unit 18and to transfer interrupt state information to the processing unit 18.

Referring now to FIGS. 3-5, there is shown schematic diagrams of theintegrated latch 60 for latching the console drive housing 30 in theclosed position and unlatching the top housing 30 to allow the housing30 to move to the open position. The latch 60 includes a wire form latchpin 62 that is attached to the bottom of the console base 32 by threesupports 64, 66 and 68. The first support 64 attaches the wire 62 to thebase 32. The second support 66 is used to prevent the wire 62 frommoving vertically up or down and horizontally to the right. The thirdsupport 68 prevents the wire 62 from moving horizontally to the left.Accordingly, all three supports 64, 66 and 68 cooperate with each otherto secure latch wire 62 to the base 32 and prevent it from movingvertically or horizontally. In addition, the wire 62 is made of aflexible material such that when a horizontal force is exerted on theend 70 of the latch wire 62 the three supports 64, 66 and 68 serve aspositioning elements to center and bias the latch wire 62 whenundeflected in a preselected position. A support bar 72 having a groove74 therein supports the wire end portion 70 and allows horizontalmovement thereof.

The latch 60 further includes a track 76 which is integral with andprotrudes from inside the console top cover 42. The track 76 includes alower triangular track 78 and an upper notch 80. The dashed line 82shows the equilibrium or center position of wire end 70 (:i.e., theposition of wire end 70 when no external forces are exerted thereon).

In operation, as the top cover 42 is moved from the open position to theclosed position, the wire end portion 70 contacts the track 78 at A andtravels along path 84 and then comes to rest at position B. As the wireend 70 travels along path 84 the track 78 pushes the end 70 to the rightbut since the wire is trying to return to its center position 82, thewire end 70 will ride adjacent track 78 in path 84. Once the wire end 70passes the first nub 86 it will move to the left and into 88 and thenfinally resting and being held at position B by second nub 90 and itsspring force pushing the end 70 toward the center position 82 into nub92. At position B the top cover 42 is latched in the closed position asthe upward force exerted by top cover 42 and track 78 is stopped by thewire end 70.

To unlatch the top cover 42, a user presses on the pad 34 and as the topcover 42 is moved from the closed position to the open position, thenotch 80 and track 78 will first move downward and the wire end 70 willmove toward its center position 82. Once the second hub 90 of track 78is below the horizontal level of the wire end 70, the end 70 will moveto center line 82. The top cover 42 then moves upward by theraise/support assembly (described below) and the wire end 70 travelsalong path 92 and then come to rest at position C. The wire end is atits center position at position C and the cover 42 is fully open.

The integrated latch assembly 60 provides positive latching withoutadditional, discrete latching parts which provides for simple,error-free, and consistent latch operation while also minimizing thenumber of moving parts.

Referring now to FIGS. 3 and 6, there is shown schematic diagrams of theraise/support assembly 100 which allows the drive housing 30 (FIGS. 1-3)to reside within the main console base 32 when latched and raise in asmooth, fluid motion from the console base 32 when unlatched and remainsupported in the open position in accordance with the present invention.In addition, the raise/support assembly 100 provides the resiliency thata user feels when pushing on the push pad 34 when moving the drivehousing 30 from the open position to the closed position. The assembly100 includes a wire form spring 102 held in place by the tab 104 inconsole base 32 and holes 106 in DASD bracket 44 of the console topcover 42, the latter of which attaches the ends 108 of spring 102 to thedrive housing 30. The spring 102 provides the lifting force to raise thehousing 30 when unlatched. The spring 102 has a non-linear force profile(i.e., the spring does not compress linearly with position of thehousing 30). One type of non-linear force profile is where the spring102 has approximately equal force at the open and closed positions buthas less force therebetween (e.g., a bi-center or bi-polar spring).Another type of non-linear force profile is where the spring 102 hasmore upward force in the open position than in the closed position orvice-versa. Either of these profiles can be used in the presentinvention and the discussion below will use the latter profile as anexample.

The spring 102 is biased toward position D and in cooperation with snaptabs 110 support and hold the top cover in the open position whenunlatched. When the drive housing 30 is in the closed (latched) positionthe spring end 108 is at position E and is exerting an upward force ondrive housing 30 but the housing is prevented from moving up to the openposition by the push-push latch 60 described above.

Hinge pins 112 (FIG. 3) at the rear of the top cover 42 fit withingrooves 114 in the base 32 and cooperate with each other to provide thepivot point for the drive housing 30. Snap tabs 110 on each side of thetop cover 42 provide a hard stop for the housing 30 under load from thespring 102 when moved to the open position. When moving the drivehousing 30 into the closed position, the front of the drive housingabuts a front ledge of the base member 32 to prevent any furtherdownward movement of the housing 30.

Centrifugal geared dampers 116 are attached to each end of the consoletop cover 42 by platform members 118 and a screw 120 (see FIG. 3)inserted into the opening on the platform member 118 and into a boss(not shown) in the top cover 42. The geared dampers 116 control thespeed of ascent of the drive housing 30 and dampen spring oscillations.Each damper 116 includes platform member 118 which holds circular roller122 allows it to freely rotate. The circular roller 122 is held bycircular edges 123 of the platform member 118. The rollers 122 includesan integral gear 124 which rides along a cooperating radiused gear track126 when the top cover moves up or down. The gear track 126 is designedto match an arc of a moving point rotating about a fixed pivot pointsince the drive housing 30 pivots about the fixed hinge pins 112 andgrooves 114. The radiused design of gear track 126 allows the damper 116to flow smoothly when the housing 30 is opened or closed.

In operation, when the drive housing 30 is latched in the closedposition, the spring end 108 is at position E exerting an upward forcebut held closed by the latch 60. When a user presses down on push pad34, the housing 30 is unlatched (as described above) and the spring end108 exerts an upward force on the housing 30 as it moves from position Eto position D and the dampers 116 cushion and smooth out that movementas they move from position F to position G along the gear track 126. Thedrive housing 30 is then held in the open position by spring ends 108and the snap tabs 110 prevent the housing 30 from going up any further.Thus, the spring 102, geared dampers 116 and gear tracks 126 provide araise/support assembly which allows the drive housing 30 to movesmoothly from the closed position to the open position when housing 30is unlatched.

To close the drive housing 30, a user presses on the pad 34 with asufficient force to overcome the upward force of spring 102. This willmove the spring ends 108 from position D to slightly past position E asthe dampers 116 move from position G to slightly past position F and thefront ledge of the base member 32 prevents any further downward movementof cover 42. The spring ends 108 and dampers 116 will then move toposition E and F respectively and the housing 30 will be latched in theclosed position by latch 60 (described above).

The raise/support assembly 100 of the present invention allows the drivehousing 30 to reside within the main console base 32 when latched, butraise in a smooth, fluid motion from the console base 32 when unlatchedand remain supported in the open position. The assembly 100 is based ona wire form spring 102 that provides significant function withoutrequiring several moving parts or linkages thus providing a lowcomplexity of assembly. The damper action against molded-in gear racks126 provide effective dampening and consistent control of the housing 30ascent with minimal complexity of design.

Referring now to FIG. 7, there is shown a schematic diagram of the towertype system unit 18 of the present invention. As mentioned above, theprocessing unit 18 is designed to be placed on the floor and containssystem components which the user does not need to interact withregularly. More specifically, the system unit 18 contains the remainderof the computer components including a microprocessor, memory,video/graphics subsystem, hard disk drive(s), expansion bus slots(PCI/ISA), expansion drive bays, power supply and fan(s). Accordingly,the processing unit 18 contains all of the high power, bulky and noisycomponents that the user does not need to interact with. Unless the userchooses to install an accessible drive (like a 5.25" floppy drive ortape backup unit) the processing unit can be completely hidden fromview. The multi-conductor electrical cable 20 connecting the processingunit 18 and the media console 16 allows the processing unit 18 to beplaced along side, underneath or even behind the desk supporting themedia console 16, or in a different room or office than the mediaconsole 16.

More specifically, the system unit 18 includes an internal mounting orbase chassis assembly 130 disposed within an outer decorative cover 132.Cover 132 has a handle to allow for easy carrying or moving of the towertype processing unit 18. A power supply 134 for supplying power to boththe processing unit 18 and the media console 16 is disposed within anupper portion of the assembly 130. A hard disk drive 136 is attached tothe top of the assembly 130 by screws 138. The hard disk drive 136 is afixed medium direct access storage device capable of storing anddelivering data as is generally known. A planar 140 is mountedvertically in the right side portion of assembly 130 and includes acentral processing unit (CPU) 142, ports 144 for connecting additionalRAM memory and a riser card port 146 for connecting a riser card 148.The planar 140 provides a means for electrically interconnecting thecomponents of the computer 10 including those identified above. Thesystem unit 18 also includes a modem/sound card 150 coupled to anexpansion bus slot (see FIG. 9A). An expansion bus interface card 152 isdisposed within the assembly 130 and is coupled between anotherexpansion bus slot and the multi-conductor cable 20. The interface card152 will be described in more detail below.

System unit 18 also includes a fan (not shown) disposed behind fan vent154 for cooling the components of system unit 18 such as the CPU 142,graphics controller, hard disk drive 136 and power supply 134. Since thetower or base unit 18 is meant to be placed under a table or desk, thevolume of the enclosure is less critical (1) allowing the fan inside tocirculate air inside the unit 18 rather than through it allowing forquieter cooling and (2) allowing the unit 18 to be cooled with optionalheat pipes (not shown) that bring the heat to outer surfaces of the box.

A television card 156 is also disposed within processing unit 18 andcoupled to an expansion bus slot (FIG. 9A). The TV card 156 allowsstandard television signals from a coaxial cable or composite videoinput to be tuned and subsequently displayed in a window on the monitor12. A 40 pin ribbon cable 158 is used to couple the output of the TVcard 156 to the graphics subsystem. An electromagnetic interference(EMI) shield 160 is disposed between the cover 132 and chassis 130.

The processing unit 18 includes other elements which are conventionaland as such are not described herein.

Referring now to FIG. 8, there is shown an alternative embodiment of theprocessing unit 18 wherein a subwoofer 162 has been integrated therein.The subwoofer 162 is integral with the system unit 18 and is disposed ata bottom thereof. The subwoofer 162 fits under the cover 132 and is partof the system unit's base 164. The subwoofer includes vents 166 onopposite sides of the base 164 for allowing acoustic energy to escape. Ashield 168 is disposed between the hard disk drive 136 and the subwoofer162 for shielding a magnetic field that emanates from the subwoofer'smagnet. The shield 168 can be made of a metal such as for example,mumetal, aluminum or iron.

The addition of the integrated subwoofer 162 to the processing unit 18has the added advantage of saving space by reducing the number ofseparate system components (i.e., combining system unit and subwoofer),reduces complexity and connections for the end user. In addition, theintegrated subwoofer 162 reduces cost by sharing the same enclosure andsystem power supply.

Prior to relating the above structure to the present invention, asummary of the operation in general of the personal computer system 10may merit review. Referring to FIGS. 9, 9A, 9B, and 9C, there is shown ablock diagram of a personal computer system illustrating the variouscomponents of the computer system such as the system 10 in accordancewith the present invention, including components mounted on the planar140 and the connection of the planar to the I/O slots and other hardwareof the personal computer system. Connected to the planar 140 is thesystem CPU or processor 142 which is connected by a high speed CPU localbus 170 through a memory control unit 172, which is further connected toa volatile random access memory (RAM) 174. The memory control unit 172is comprised of a memory controller 176, an address multiplexer 178, anda data buffer 180. The memory control unit 172 is further connected toRAM 174 as represented by the four RAM modules 182. The memorycontroller 176 includes the logic for mapping addresses to and from themicroprocessor 142 to particular areas of RAM 174. This logic is used toreclaim RAM previously occupied by basic input output system (BIOS).Further generated by memory controller 176 is a ROM select signal(ROMSEL), that is used to enable or disable ROM.

While the present invention is described hereinafter with particularreference to the system block diagram of FIGS. 9, 9A, 9B, and 9C, it isto be understood at the outset of the description which follows that itis contemplated that the apparatus and methods in accordance with thepresent invention may be used with other hardware configurations of theplanar board. For example, the system processor 142 could be an IntelPENTIUM processor, Cyrix 586-P75 processor or Advanced Micro Devices8486 processor or any other suitable microprocessor.

Returning now to FIGS. 9, 9A, 9B, and 9C, the CPU local bus 170(comprising data, address and control components, not shown) providesfor the connection of the microprocessor 142, a math coprocessor 184 (ifnot internal to the CPU 142), a system cache memory 186, and a cachecontroller 188. Also coupled on the CPU local bus 170 is a core chipset190 which includes a peripheral component interconnect (PCI) bridge andan integrated drive electronics (IDE) fixed disk controller. The corechipset 190 can be an Intel Triton VX chip and an Intel PIIX3 chip. ThePCI bridge within chipset 190 provides an interface between the localbus 170 and a PCI bus 196. Connected to the PCI bus 196 are a pluralityof I/O slots 198 for receiving peripheral devices, one of which is avideo controller 200. The video controller 200 has associated with it amonitor (or video display terminal) 12 and a video memory 202.

The chipset 190 is itself connected to a slower speed (compared to theCPU local bus 170) system bus 204, also comprising address, data andcontrol components. The system bus 204 extends between the chipset 190and a buffer 206. The system bus 204 is further connected to a buscontrol and timing unit 208 and a DMA unit 210. The DMA unit 210 iscomprised of a central arbiter 212 and a DMA controller 214. Anadditional buffer 216 provides an interface between the system bus 204and an optional feature or expansion bus 218 such as the IndustryStandard Architecture (ISA) bus. Connected to the bus 218 are aplurality of I/O slots 220 for receiving ISA adapter cards, one of whichis a host interface ISA card 152 (another of which is the modern/soundcard 150). Additional ISA adapter cards can be pluggably connected tothe I/O slots 220 and may provide additional I/O devices or memory forthe system 10. The host card 152 is connected by the multi-conductorcable 20 to the electronic card 56 which is disposed in the mediaconsole 16. The host card 152, cable 20 and console electronics card 56will be described in more detail below. It is sufficient at this pointto note that the electronics card 56 includes a de-multiplexer 222 whichis coupled to a keyboard controller 224, a 8277 diskette adapter 226 andan IDE disk controller 228 via bus 230. The keyboard controller 224, isthe slave processor that interfaces with the keyboard 14 and the mouse15. The de-multiplexer 222 is also coupled to the power switch 26 andthe power/feedback LED 28. The keyboard controller 224, FDD controller226 and IDE disk controller 228 can all be included in a single superI/O circuit such as for example, a SMC37C932 chip.

An arbitration control bus 232 couples the DMA controller 214 andcentral arbiter 212 to the I/O slots 220 and another diskette adapter234.

While the microcomputer system 10 is shown with a basic 8 megabyte RAMmodule 174, it is understood that additional memory can beinterconnected as represented in FIGS. 9A and 9B by the addition ofoptional higher-density memory modules 182. For purposes of illustrationonly, the present invention is described with reference to the basiceight megabyte memory module.

A latch buffer and decoder 206 is coupled between the system bus 204 anda planar I/O bus 236. The planar I/O bus 236 includes address, data, andcontrol components respectively. Coupled along the planar I/O bus 236are a variety of I/O adapters and other components such as the disketteadapter 234, an interrupt controller 238, an RS-232 adapter 240,nonvolatile CMOS RAM 242, also herein referred to as NVRAM 242, a CMOSreal-time clock (RTC) 244, a parallel adapter 246, a plurality of timers248, the read only memory (ROM) 250, the keyboard controller 252, andthe power management circuitry 254. The keyboard controller 252 anddiskette adapter 234 are duplicated in the media console 16 in order toallow additional diskette drives or tape drives to be installed in thesystem unit 18 (via 234), or the keyboard and mouse can be plugged intothe system unit 18 instead of the console 16 (via 252). In addition, theduplication allows the same planar to be used without such a console 16.The power management circuitry 254 is in circuit communication with thepower supply 134, the switch 26, the power/feedback LED 28, and aninternal modem 256 and/or an external modem 258. The external modem 258is typically connected to a transformer 260, which is connected to atypical wall outlet, as is known to those skilled in the art. The modems256, 258 are connected to a typical telephone outlet.

The read only memory 250 includes the BIOS that is used to interfacebetween the I/O devices and the operating system of the microprocessor142. BIOS stored in ROM 250 can be copied into RAM 174 to decrease theexecution time of BIOS. ROM 250 is further responsive (via ROMSELsignal) to memory controller 176. If ROM 250 is enabled by memorycontroller 176, BIOS is executed out of ROM 250. If ROM 250 is disabledby memory controller 176, ROM is not responsive to address inquiriesfrom the microprocessor 142 (i.e. BIOS is executed out of RAM).

The real-time clock 244 is used for time of day calculations and theNVRAM 242 is used to store system configuration data. That is, the NVRAM242 will contain values which describe the present configuration of thesystem 10. For example, NVRAM 242 contains information describing thecapacity of a fixed disk or diskette, the type of display, the amount ofmemory, time, date, etc. Furthermore, these data are stored in NVRAM 242whenever a special configuration program, such as SET Configuration, isexecuted. The purpose of the SET Configuration program is to storevalues characterizing the configuration of the system to NVRAM 242.

The interface card 152, multi-conductor cable 20 and media electronicscard 56 will now be described with reference to FIGS. 10-14. The ISAinterface card 152 allows IDE controller 228, FDD controller 226 and8042 keyboard controller 224 to be used in the media console 16. The ISAcard 152 which is plugged into the base system unit 18 can be programmedto decode certain ranges of I/O addresses. The BIOS ensures that theproper I/O ranges for the devices in the console 16 ("split" devices)are enabled and that possibly conflicting planar devices are disabled.When the interface card 152 detects a valid input/output (I/O) or directmemory access (DMA) cycle for a split device, it intercepts the cycleand issues the I/O (or DMA) cycle to the media console 16 electronicscard 56 which responds to the I/O (or DMA) cycle.

A multiplexing scheme was developed to multiplex address, data, andinterrupts in order to keep the number of signals in the cable 20 to areasonable number. In addition to the multiplexed I/O signals, someother signals had to be brought up independently--auxiliary 5 volts, thepower light indicator signal, and the power switch signal. These signalsmust be separate because they must be active even when the main power isoff.

The present invention provides a generic ISA bus I/O extender interfacethat minimizes the number of signals needed to transfer data, addressand interrupts between devices in the consol 16 and devices n the systemunit 18. In addition, the present invention allows the media console 16electronics to be based around a super I/O device 286 that contains theIDE, FDD and keyboard controllers 228, 226 and 224 respectively. Inaddition, new devices could easily be added simply by adding theappropriate decode range to the base card and adding the ISA device tothe media console 16 with no changes to the cable 20 protocol.

Referring now to FIG. 10, there is shown a schematic diagram of the ISAinterface card 152, the media card 56 and the coupling therebetween viathe multiconductor cable 20. The interface card 152 includes amultiplexer 270 for multiplexing addresses from the ISA bus 218, datato/from the ISA bus 218 and interrupt requests (IRQs) from the console16 to the ISA bus 218. Multiplexer 270 includes a tristateable addressdriver 272 coupled to the address signals of ISA bus 218, a tristateabletransceiver 274 coupled to the data signals of ISA bus 218 and an IRQlatch 276 coupled to the control portion of ISA bus 218. A sequencer orcontrol circuit 278 is coupled to the address and data signals of theISA bus 218 and multiplexer 270. Configuration registers 280 are used byBIOS to enable the appropriate I/O address ranges and DMA channels forthe sequencer 278 to pass through to the media console 16. A descriptionof the registers 280 and an unlocking/locking sequence is describedbelow.

The sequencer 278 constantly monitors the ISA bus 218 waiting for I/O orDMA cycles that it must act upon. During ISA bus idle times, the addresssignals are constantly driven through the multi-conductor cable 20 tothe media console 16. When the sequencer 278 detects an I/O cycle thatneeds to be passed through to the media console 16, the address enablesignal (ADR₋₋ EN) is deasserted to latch the address into the mediaconsole 16 and tristate the cable data bus 282 (MUX DATA). Next, thedata enable (DAT₋₋ EN#) is asserted to enable the data transceivers topass the data to/from the media console 16 across the multi-conductorcable data bus 282.

At the end of each I/O and DMA cycle (even those not decoded) as well asmemory refresh cycles, the sequencer 278 samples the 8 IRQ signals thatthe media console 16 is capable of generating (IRQs 1, 3, 6, 9, 11, 1214 and 15). The media console 16 was designed to only generate 8 IRQsand allow a single byte to be transmitted. It should be understood thatthe media console 16 could be designed to generate 16 IRQs but thiswould increase cost. The 8 IRQs chosen are typical ones used by thedevices in the console 16 (e.g., IRQ1 for the keyboard 14, IRQ6 for thefloppy disk drive 22, IRQ 12 for the mouse 15 and IRQ15 for the CD-ROMdrive 24. Extra IRQs (IRQs 3, 9, 11 and 14) are included to allow aPlug-n-Play operating system to reconfigure the IRQs. The sequencer 278activates the IRQ strobe signal (IRQ₋₋ STRB#) for one clock cycle. Inresponse to this signal, the media console 16 drives the current stateof the interrupts onto the cable data bus 282. The IRQ latch 276 thenlatches the interrupt states and drives them onto the ISA channel withopen collector drivers. This IRQ cycle overlaps the ISA bus I/O recoverytime so that there is no performance penalty. No interrupts are lostsince all devices generate interrupts in a level triggered fashion. Aninterrupt never occurs as a short pulse as they are always latched bythe generating device and it requires action by the CPU 142 (usuallyreading a status I/O port) to clear the IRQ.

The electronics card 56 in the media console 16 is an I/O busdemultiplexer. The demultiplexer 222 includes an address latch 284 forlatching the addresses from the base card 152. A super I/O device (SIO)(e.g., SMC 37C932) 286 is coupled to the address latch 284, the FDD 22,the CD-ROM 24, the sequencer 278, the tristateable transceiver 288 andthe IRQ tristateable buffer 290. As noted above, the SIO device 286contains the diskette adapter 226 and IDE disk controller 228 for thefloppy disk drive 22 and CD-ROM drive 24 respectively. The demultiplexer222 is a slave to the sequencer 278 in the base card 152. Morespecifically, the demultiplexer 222 responds to the address enable(ADR₋₋ EN) and data enable (DAT₋₋ EN#) signals generated by thesequencer 278 and the IRQ strobe (IRQ₋₋ STRB#) signal also generated bythe sequencer 278 to latch/drive the appropriate signal groups.

The output of the demultiplexer 222 is a pseudo ISA bus in that it doesnot support all I/O addresses, memory cycles, master cycle etc. butrather only carries certain I/O address ranges. In addition, this pseudoISA bus only carries up to 3 DMA channels and 8 IRQ signals. One DMAchannel (channel 2) is used for the floppy disk drive 22 and the othertwo channels are spares. The 3 DMA channels and 8 IRQs were chosen to besufficient for the devices currently in the console 16 and allowupgrades as well with the unused DMA channels and IRQs. Of course, moreDMA channels and IRQs would require more conductors in the cable 20. Thesetup and hold timings for the pseudo ISA bus are slightly morestringent than the ISA bus 218. The timing restrictions are due to theadditional propagation delays through the buffers and cable 20. Thesuper I/O integrated circuits available today have much less setup andhold specifications than the original ISA bus allowed for. This allowsthe split system 10 of the present invention to operate with noadditional wait states.

The host interface card 152 is configured to pass the appropriate I/Oaddresses through to the media console 16. In addition, the console 16is programmed to respond to the appropriate addresses as well. It shouldbe noted that interrupt request levels do not need to be programmed asthey are automatically passed through from the media console as they aregenerated. This is possible because they are driven back to the ISA bus218 using open collector drivers (i.e., output of IRQ latch 276).

The sequencer 278 is configured through a pair of 8 bit I/O ports orregisters 280 within sequencer 278; a first I/O port (CFG₋₋ ADDR) ataddress 370H and a second I/O port (CFG₋₋ DATA) at address 371H. TheCFG₋₋ ADDR register is a write only register which is used to open andclose the configuration space and to select one of the configurationregisters. Bits 0-3 of this register are Index bits and bits 4-7 areunused. The CFG₋₋ DATA register is a read/write register used to accessthe configuration register currently specified by CFG₋₋ ADDR. Bits 0-3of this register are used for data and bits 4-7 are unused.

The configuration registers are unlocked by writing the followingsequence to the CFG₋₋ ADDR register: "ODH", "OCH". The logic withinsequencer 278 enters the first stage of the unlock sequence after the"ODH" is received. It is important that the "OCH" be receivedimmediately afterwards because any other output cycle (even to anotherI/O port) will reset the lock. Once unlocked, the configurationregisters 280 can be accessed until the locking key ("OFH") is received.Also when the configuration is unlocked, any configured decodes aredisabled.

The following configuration registers 280 are used to select theappropriate I/O and DMA cycles to route through to the media console 16:

    ______________________________________                                        IDE.sub.-- MISC                                                                       index 0    Default = 0                                                        Bit 1 . . . 0                                                                            00 - Enable no IDE                                                            01 - Enable IDE1:1F0H-1F7H,3F6H                                               10 - Enable IDE2:170H-177H,376H                                               11 - Enable IDE3:1E0H-1E7H,3E6H                                    Bit 2      Enable programmed I/O ranges. "0"                                             means computer system IF is off.                           FDD.sub.-- DCD                                                                        index 1    Default = 0                                                        Bit 0      Enable FDD1:3F0H-3F7H                                              Bit 1      Enable FDD2:370H-377H                                              Bit 2      Enable SMI generation on write to                                             FDD control port. This bit is cleared                                         when the SMI occurs. This bit also                                            enables shadow writes to the                                                  FDD1 address range                                                            even when bit 0=0.                                         DMA.sub.-- ACK                                                                        index 2    Default = 0                                                        Bit 1 . . . 0                                                                            00 - Enable no DACK cycles                                                    01 - Enable DACK0 cycles                                                      10 - Enable DACK1 cycles                                                      11 - Enable DACK2 cycles                                           Bit 2      Enable all I/O address ranges                                                 (use for configuration only).                              KBM.sub.-- DCD                                                                        index 3    Default = 0                                                        Bit 0      Enable 8042 I/O address ranges. This                                          bit also automatically enables SMIs                                           for reset/A20 emulation (SMI occurs                                           for writes of X1, XC, XD, XE, XF to                                           "64"). The bit is cleared when                                                the SMI occurs. Enable SMIs on writes                              Bit 1      to port "60". The bit is cleared                                              when the SMI occurs.                                       ______________________________________                                    

Turning now to FIG. 11, there is shown a cycle timing diagram of a 16bit I/O cycle through the ISA interface of the present invention. Thecycle timing is characteristic of a block read of data from the CD ROM24. More specifically, a device in system unit 18 generates an ISAaddress at A. The sequencer 278 detects that this is an ISA addressdirected to the media console 16. As stated above, the sequencer 278,during bus idle times constantly drives the address signals through thecable 20 to the media console 16. Accordingly, at point B themultiplexer 270 provides the ISA address to the media consoleelectronics card 56 via the cable 20. At C the sequencer 278 deassertsthe ADR₋₋ EN to latch the address into the media console 16 and tristatethe cable data bus. Next, the demultiplexer 222 switches to provide dataon its output at D, the data is then transferred to ISA bus 218 at E,and the device requesting the data then latches the data at point F. TheI/O read cycle also ends at F when the requesting device driving the ISAbus 218 deasserts the IOR₋₋ signal. The sequencer 278 then activatesIRQ₋₋ STRB# for one cycle at G. In response thereto the media consoleelectronics card 56 drives the current state of the interrupts onto thecable data bus at H. The IRQ states are latched into IRQ latch 276 atpoint J.

As shown in FIG. 11, the I/O read cycle takes 312 nsec and the recoverytakes 563 nsec to yield a total cycle time of 875 nsec for a 16 bit IOread. This yields a maximum sustained transfer rate of 2.3 MB/sec.

The main connection between the host interface 152 and the planar 140 isthe ISA bus 218 itself. All ISA bus signals used are bufferedappropriately so that the multi-conductor cable 20 and media console 16do not adversely affect the ISA bus loading. There are a few othersignals that must be picked up from sources other than the ISA bus 218.As noted above, these signals include AUX5, the power light indicatorsignal and the power switch signal. The red book audio interface fromthe CD-ROM 24 is included in the multi-conductor cable 20 and madeavailable on the host interface card 152. The connector has been chosensuch that the same cable that is currently used to connect the CD andsound card can be used between the host interface card 152 and soundcard. Various other signals are required from the planar. Many of theseare available through existing planar connections. However, to reducethe number of discrete jumper cables required and ease assembly of thesystem unit 20, all necessary signals have been incorporated into asingle 10 pin (2×5) connector on the planar 140 which is connected toplanar connector 292 on the ISA card 152. Each of the signals of the 10pin connector along with their function description are shown in thetable of FIG. 12.

Turning now to FIG. 13, there is shown a power distribution between thehost interface card 152 and media electronics card 56 of the presentinvention. Since the media console 16 is powered through themulti-conductor cable 20, the necessary voltage (+12VDC) is obtained byusing one of the large DASD connectors 294 from the power supply. Thisavoids the potential problem of pulling too much current through the ISAedge connector. The number of available DASD connectors should not be anissue because the CD-ROM 24 is not located in the base unit 18 of thesplit system 10. The power voltages that exit the system through themulti-conductor cable 20 connector go through a 2.5 amp resettable fuseto prevent cable or circuit damage in the event of a short.

Bulk +12V is provided to the media console 16 from cable 20. This isused to provide power to the CD-ROM and floppy disk drive DASDconnectors 296, and 298 respectively. (It should be noted that +12V isstill available in the DASD connector 298 to the floppy disk drive 22even though current FDD's typically do not use +12V motors.) There isalso a current limited +12VDC bulk voltage that is used to regulate downto +5VDC. In order to handle the current requirement of each componentof the media console 16, 3 independent regulators are implemented. Oneregulator 300, is for the 5VDC supply to the electronics (includingkeyboard and mouse), another regulator 302 is for the 5VDC to the floppydisk drive power connector 298 and a third regulator 304 is for the 5VDCfor the CD-ROM power connector 296. The current to all three regulatorsis limited by a voltage dropping resistor 306. This resistor has beenchosen to be a 2.4 ohm 10 watt resistor. Therefore the three regulatorscan supply a total of about 2 amps of current before dropping out ofregulation. The regulators are attached to a sufficient heat sink toprevent overheating. The dropping resistor 306 is physically located onthe host card 152 in the processing unit 18 so that the total heatdissipation would not be concentrated in the media console 16 wherethere is no fan. This means that there are two bundles of powerconductors in the multi-conductor cable: +12VDC and +12V₋₋ DROP.

The multi-conductor cable 20 is a 28 gauge, 50 conductor cable composedof 25 pairs with a 50 pin Centronics connector on one end (SCSI) whichconnects to the Centronics connector 153 on host card 152 and a 50 pinheader connector on the other end which connects to a connector port 58on media console 16. The table in FIG. 14 shows the signal layout of theheader. The cable 20 can be in a range of between 4 and 7 feet long with61/2 feet being the preferred length. The cable 20 allows the processingunit 18 to be placed along side, underneath or even behind the desksupporting the media console 16, or in a different room or office thanthe media console 16.

While the invention has been particularly shown and described withrespect to preferred embodiments thereof, it should be understood bythose skilled in the art that the foregoing and other changes in formand detail may be made therein without departing from the spirit andscope of the invention as defined in the appended claims,

What is claimed is:
 1. A computer system comprising:a media consolehaving a base member and a drive housing that can be moved within saidbase member between an open position and a closed position, a springconnected to a bottom of said base member and to said drive housing forbiasing said drive housing in said open position, a pair of gear tracksintegrally formed in opposite sides of said base member for cooperatingwith a pair of geared dampers attached to opposite ends of said drivehousing, said drive housing having a direct access storage devicedisposed at a front end thereof, said direct access storage devicehaving an opening for receiving a removable storage medium, and whereinsaid spring, gear tracks and geared dampers cooperate with each other(1) to allow said drive housing to move smoothly from said closedposition to said open position wherein a user may access said opening,and (2) to allow said drive housing to move smoothly from said openposition to said closed position.
 2. The computer system of claim 1,wherein said pair of gear tracks have a shape corresponding to an arcformed by a radial line rotated about an end of said base member.
 3. Thecomputer system of claim 1, wherein said geared dampers include acircular roller with an integral gear rotatably attached to a holdingelement which is attached to said drive housing.
 4. The computer systemof claim 1, further including a latch integrally formed in said drivehousing and cooperating with a latch member in said base member forlatching said drive housing in a closed position.
 5. The computer systemof claim 1, wherein said spring is a wire form spring having anon-linear force profile wherein an amount of force applied in said openposition is less than an amount of force applied in said closedposition.
 6. The computer system of claim 1, wherein said spring is awire form bi-polar spring having a non-linear force profile wherein anamount of force applied in said open and closed position issubstantially the same and an amount of force applied while moving fromsaid open to said closed position or vice-versa is less than saidsubstantially same force.
 7. The computer system of claim 1, whereinsaid direct access storage device is a floppy disk drive and saidremovable storage medium is a floppy disk.
 8. The computer system ofclaim 7, wherein said drive housing further includes a CD-ROM drivehaving an opening for receiving a compact disk.
 9. The computer systemof claim 7, wherein said base member has an opening disposed therein anda front panel integrally disposed at a front of said base member, saidfront panel defining a front of said opening,wherein said closedposition is characterized in that said drive housing is disposed withinsaid opening of said base member and said opening in said floppy diskdrive is behind said front panel and not accessible by said user, andwherein said open position is characterized in that a front portion ofsaid drive housing is not within said opening of said base member andsaid opening in said floppy disk drive is above a top of said frontpanel and is accessible by said user.
 10. The computer system of claim9, wherein said drive housing further includes a CD-ROM driveelectrically coupled to said electrical connector and having an openingfor receiving a compact disk,wherein said closed position is furthercharacterized in that said opening in said CD-ROM drive is behind saidfront panel and not accessible by said user, and wherein said openposition is further characterized in that said opening in said CD-ROMdrive is above a top of said front panel and is accessible by said user.11. The computer system of claim 9, wherein said drive housing includesa substantially flat top cover which is substantially flush with a topof said front panel of said base member when said drive housing is insaid closed post.
 12. The computer system of claim 9, wherein said basemember includes a substantially flat bottom, substantially verticalfront panel and opposing side panels and wherein said recess is definedas an opening formed by said front and opposing side panels.
 13. Thecomputer system of claim 9, wherein said drive housing is pivotallymounted to a back end of said base member for allowing said drivehousing to pivot between said open and closed positions.
 14. Thecomputer system of claim 13, wherein said drive housing includes a hingepin at opposite ends of a back portion of said drive housing, said basemember includes a groove at each end thereof and wherein said pair ofhinge pins fit within said grooves to provide a point from which saiddrive housing can pivot between said open and closed positions.
 15. Thecomputer system of claim 1, wherein said direct access storage device isa CD-ROM drive and said removable storage medium is a compact disk. 16.The computer system of claim 1, wherein said drive housing is pivotallymounted to an end of said base member for allowing said drive housing topivot between said open and closed positions.
 17. The computer system ofclaim 16, wherein said pair of gear tracks have a shape corresponding toan arc formed by a radial line rotated about said end of said basemember.